For the steak: Preheat a grill or grill pan to medium high.
Sprinkle the skirt steak with the salt and drizzle with the olive oil. Place on the grill and cook to the desired doneness, 4 to 6 minutes per side, depending on the thickness. (The outside of the steak should have a golden-brown char.) Remove to a platter and squeeze the lemon half over the steak. Let rest for 10 minutes.
For the herb sauce: Meanwhile, put the shallot, basil, mint, parsley, olive oil, salt, lemon zest, lemon juice, almonds and paprika in a medium bowl. Mix together until combined.
Cut the steak on the bias into 1/2-inch-thick slices, against the grain. Serve with the herb sauce.